The joys of a new book

This is the first time I've started planning a new book after having completed one. Oddly, this actually feels more daunting than moving on to any number of new projects has in the past. I think this may be due to the fact that I've had beta readers for my last book, and there's a sense of needing to live up to expectations.

I'm unsure about the ettiquette of sharing details of a WIP publicly on a blog. Is it frowned upon or just unwise in case someone browsing the blog should decide to steal an idea? Am I just being paranoid?

Either way, I have my protagonist named and his background decided. I could really use a working title. And some more ideas for how to write an urban fantasy set in London.